/Engine/Plugins/Online/OnlineFramework/Source/Party/Public/Party/SocialParty.h
bool ApplyCrossplayRestriction ( [FPartyJoinApproval](API\Plugins\Party\Party\FPartyJoinApproval) & JoinApproval, const [FUserPlatform](API\Plugins\Party\FUserPlatform) & Platform, const [FOnlinePartyData](API\Plugins\OnlineSubsystem\Interfaces\FOnlinePartyData) & JoinData ) const